I hate to tell you this but I worked with a lot of anti-communist and anti-censorship efforts in the early 2000s.

The Chinese Government intelligence agencies are quite adept at using social media. People were "disappeared" with frightening regularity. Someone getting on the Chinese equivalent of the "Do Not Fly List" is pretty easy.

You can probably see it happen in person if you go to a local "police" station and ask about Tiananmen Square....